1. Field of the Invention
The invention relates to stacking towers and more particularly to a pollution control system for use with a stacking tower.
2. Prior Art
Many large coal users store their coal in large stockpiles in an open area to achieve maximum accessibility for management of the coal. This storage may be accomplished with the aid of a steel or concrete cylindrical stacking tower having a series of vertically spaced pairs of openings. Each of the openings in a pair are located in opposed sections of the tower wall and the pairs are usually spaced five to six feet vertically. The height of the stacking tower depends on the size of the stockpile desired, with most towers measuring about one hundred feet.
The stacking tower is the most economical system for large tonnage coal storage and therefore most consultants and engineers recommend its use. Unfortunately, the stacking tower is not environmentally clean and some environmental agencies have taken a firm stand against the open stockpiling of coal because of the large volume of fugitive dust generated by the stockpiling operation.
The stacking operation involves the conveyance of the coal to the top of the tower where it drops through the tower to grade level to start the stockpile. The coal flows diametrically through the openings in the tower and is evenly distributed to the pile. This process generates large volumes of dust which emanate through openings in the tower. Additionally, ground winds blow through the openings in the tower and compound the problem.
Some of the fugitive dust will settle out within a few hundred feet of the stacking tower, however, large quantities of airborne particulates will remain suspended. The airborne particulates are the primary pollution factor which is most highly objectional for reasons of health and safety. As a result, standards have been established at various levels of the government designed to control this pollution source and inflict heavy financial penalties for violations.
Present solutions to fugitive dust control for coal stockpiling operations are very limited. The dust control options which are available and recognized by some pollution control agencies are very costly in terms of initial investment and operational expense. Foam injected dust suppressants are but one example. Another positive approach to this problem is to contain the stockpiling operation in an enclosed silo. In both cases the cost is prohibitive.
The present energy crisis has created a renewed interest in and a greater demand for coal. The instant invention will allow the modification of existing stacking towers so that environmental regulations may be followed and the cost of coal storage kept at a reasonable level.
It is therefore an object of this invention to provide a stockpiling tower compatible with pollution laws and regulations that is cost effective.
It is another object of the invention to provide a versatile system which can control the problem of fugitive dust under a variety of ambient conditions during various stages of the stacking operation.